A 29-year-old woman comes to the clinic because of double vision and drooping of both eyelids that worsen by the end of the day. She also reports difficulty chewing meat at dinner after being able to eat breakfast normally. Examination shows fatigable ptosis and normal pupillary responses. Which of the following is the most likely underlying mechanism of her disorder?
- A)Segmental demyelination of peripheral nerves after infection
- B)Mutation causing absent dystrophin in skeletal muscle
- C)Autoantibodies against postsynaptic nicotinic acetylcholine receptorsGABARITO
- D)Autoantibodies against presynaptic voltage gated calcium channels
- E)Degeneration of upper and lower motor neurons
Explicação
Myasthenia gravis causes fluctuating ocular and bulbar weakness that worsens with use and improves with rest. The underlying lesion is usually IgG mediated destruction of postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction, producing f... Ver explicação completa e trilha adaptativa →